Physical Sciences and Mathematics Commons^™

Modeling Overdraft-Driven Nitrate Transport In Shallow Wells For Mitigation And Scenario Planning, Jonathan Cronk

Department of Biological Systems Engineering: Dissertations and Theses

In Nebraska, average nitrate concentrations in groundwater have doubled since 1974, making water quality management more important than ever. As droughts, heat waves, and floods become more common climate events, understanding their impacts will be necessary to make informed management decisions. Emerging literature describes that drought correlates to an increase in the concentration of nitrate-N at domestic and irrigation wells, however the relative contributions of the mechanisms thought to be responsible is currently unknown.

This research assessed the impact of recharge and pumping rate changes as two mechanisms affecting nitrate-N concentration during drought, assessed the relationship between well depth and …

Does Drought Stress Eliminate The Benefit Of Elevated Co2,/Sub> On Soybean Yield? Using An Improved Model To Link Crop And Soil Water Relations, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy

Daugherty Water for Food Global Institute: Faculty Publications

Crop simulation models are indispensable tools that facilitate studies to assess climate impacts and adaptation responses, but have not been adequately tested in terms of accurately predicting crop growth and water stress responses to high carbon dioxide concentrations [CO₂]. The soybean model, GLYCIM, previously modified with a coupled leaf-level gas exchange – energy balance model, was integrated with a two-dimensional convectivediffusive root growth module which linked soil and leaf water potentials with the regulation of stomatal conductance. We evaluated the accuracy of this modified GLYCIM using experimental data from a Free-Air CO₂ Enrichment (FACE) site, SoyFACE, and …

How Is Flash Drought Understood?—Experts’ Definitions And Decision-Makers’ Perceptions, Caily Schwartz, Tonya Haigh, Mark D. Svoboda, Madeline Goebel

Drought Mitigation Center: Faculty Publications

Because flash drought is a relatively new phenomenon in drought research, defining the concept is critical for scientists and decision-makers. Having detrimental impacts on many sectors, it is important to have a consistent definition and understanding of flash drought, between experts and stakeholders, to provide early warning to the community. This study focuses on onset and progression of conditions and demonstrates the difference in flash drought identification for 15 events across six quantitative definitions of flash drought that use the U.S. Drought Monitor (USDM). Five flash drought events have been studied in the literature while 10 additional events have been …

The Patchwork Governance Of Ecologically Available Water: A Case Study In The Upper Missouri Headwaters, Montana, United States, Amanda E. Cravens, Julia B. Goolsby, Theresa Jedd, Deborah J. Bathke, Shelley Crausbay, Ashley E. Cooper, Jason Dunham, Tonya Haigh, Kimberly R. Hall, Michael J. Hayes, Jamie Mcevoy, Rebecca L. Nelson, Markéta Poděbradská, Aaron Ramirez, Elliot Wickham, Dionne Zoanni

Drought Mitigation Center: Faculty Publications

Institutional authority and responsibility for allocating water to ecosystems (“ecologically available water” [EAW]) is spread across local, state, and federal agencies, which operate under a range of statutes, mandates, and planning processes. We use a case study of the Upper Missouri Headwaters Basin in southwestern Montana, United States, to illustrate this fragmented institutional landscape. Our goals are to (a) describe the patchwork of agencies and institutional actors whose intersecting authorities and actions influence the EAW in the study basin; (b) describe the range of governance mechanisms these agencies use, including laws, policies, administrative programs, and planning processes; and (c) assess …

The Association Between Drought Exposure And Respiratory-Related Mortality In The United States From 2000 To 2018, Yeongjin Gwon, Yuanyuan Ji, Jesse E. Bell, Azar M. Abadi, Jesse D. Berman, Austin Rau, Ronald D. Leeper, Jared Rennie

Daugherty Water for Food Global Institute: Faculty Publications

Climate change has brought increasing attention to the assessment of health risks associated with climate and extreme events. Drought is a complex climate phenomenon that has been increasing in frequency and severity both locally and globally due to climate change. However, the health risks of drought are often overlooked, especially in places such as the United States, as the pathways to health impacts are complex and indirect. This study aims to conduct a comprehensive assessment of the effects of monthly drought exposure on respiratory mortality for NOAA climate regions in the United States from 2000 to 2018. A two-stage model …

The Last Drought Frontier: Building A Drought Index For The State Of Alaska, Olivia Campbell

School of Natural Resources: Dissertations, Theses, and Student Research

Drought is characterized by periods of below average precipitation. There are five major types of drought recognized in the literature: meteorological, hydrological, agricultural, socioeconomic, and ecological. A relatively new concept in the drought literature is “snow drought.” A key part of the definition of drought is that it is not always accompanied by extreme heat. This means drought can occur even in cold climates, cold seasons, and higher latitudes and altitudes, like Alaska. Drought is a natural part of climate variability, but Alaska’s climate is changing faster than any other state in the United States. Alaska is no stranger to …

Projected Long-Term Climate Trends Reveal The Critical Role Of Vapor Pressure Deficit For Soybean Yields In The Us Midwest, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy

Nebraska Water Center: Faculty Publications

Extreme climate events including heat waves and droughts are projected to become more frequent under future climate change conditions. However, the mechanisms between soybean yields and climate factors, specifically involving variable rainfall and high heat episodes, are still unclear, particularly with respect to spatial trends in the United States (US) Midwest. A recently modified version of the model GLYCIM was used to evaluate rainfed soybean production across 12 states at a 10 km spatial resolution for three time periods (2011–2020, 2051–2060, 2091–2099) under Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5. Results showed that except for the northernmost Midwest counties, …

Using Seasonal Climate Scenarios In The Forageahead Annual Forage Production Model For Early Drought Impact Assessment, M. Podebradska, B. K. Wylie, M. J. Hayes, D. J. Bathke, Y. A. Bayissa, S. P. Boyte, J. F. Brown, B. D. Wardlow

School of Natural Resources: Faculty Publications

No abstract provided.

A Workshop On Using Nasa Airs Data To Monitor Drought For The U.S. Drought Monitor, Alireza Farahmand,, Sharon Ray, Heidar Thrastarson, Stephen Licata, Stephanie Granger, Brian Fuchs

Drought Mitigation Center: Faculty Publications

Recent studies indicate that drought indicators based on near-surface air relative humidity (RH), air temperature (T), and air vapor pressure deficit (VPD), derived from the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite can detect the onset of drought earlier than other drought indicators, specifically standardized precipitation index (SPI), which is widely used for drought onset detection. A recent study showed that standardized relative humidity index (SRHI) can detect drought signals earlier than SPI (Farahmand et al. 2015). Relative humidity is a climate variable defined as the ratio of air vapor pressure to saturated vapor pressure. Precipitation and relative …

Evolution Of The Southwest Drought Learning Network: Collective Response To Exceptional Drought, E. Elias, B. Fuchs, J. Lisonbee, T. Bernadt, V. Martinez, T. Haigh

School of Natural Resources: Documents and Reviews

No abstract provided.

Comparative Behavioral Ecotoxicology Of Inland Silverside Larvae Exposed To Pyrethroids Across A Salinity Gradient, Sara J. Hutton, Samreen Siddiqui, Emily I. Pedersen, Christopher Y. Markgraf, Amelie Segarra, Michelle L. Hladik, Richard E. Connon, Susanne M. Brander

United States Geological Survey: Staff Publications

Pyrethroids, a class of commonly used insecticides, are frequently detected in aquatic environments, including estuaries. The influence that salinity has on organism physiology and the partitioning of hydrophobic chemicals, such as pyrethroids, has driven interest in how toxicity changes in saltwater compared to freshwater. Early life exposures in fish to pyrethroids cause toxicity at environmentally relevant concentrations, which can alter behavior. Behavior is a highly sensitive endpoint that influences overall organism fitness and can be used to detect toxicity of environmentally relevant concentrations of aquatic pollutants. Inland Silversides (Menidia beryllina), a commonly used euryhaline model fish species, were exposed …

Getting Ahead Of Flash Drought: From Early Warning To Early Action, Jason A. Otkin, Molly Woloszyn, Hailan Wang, Mark D. Svoboda, Marina Skumanich, Roger Pulwarty, Joel Lisonbee, Andrew Hoell, Mike Hobbins, Tonya Haigh, Amanda E. Cravens

Drought Mitigation Center: Faculty Publications

Flash droughts, characterized by their unusually rapid intensification, have garnered increasing attention within the weather, climate, agriculture, and ecological communities in recent years due to their large environmental and socioeconomic impacts. Because flash droughts intensify quickly, they require different early warning capabilities and management approaches than are typically used for slower-developing “conventional” droughts. In this essay, we describe an integrated research-and-applications agenda that emphasizes the need to reconceptualize our understanding of flash drought within existing drought early warning systems by focusing on opportunities to improve monitoring and prediction. We illustrate the need for engagement among physical scientists, social scientists, operational …

Coupling Dendrochronology And Remote Sensing Techniques To Assess The Biophysical Traits Of Juniperus Virginiana And Pinus Ponderosa Within Grassland Communities In The Semi-Arid Grasslands Of The Nebraska Sandhills, Reece Allen

School of Natural Resources: Dissertations, Theses, and Student Research

Woody species encroachment is occurring within the sandhills region in Nebraska, primarily driven by Juniperus virginiana and Pinus ponderosa, altering ecosystems and the services they provide. Effective, low cost, and cross-scale monitoring of woody species growth and performance is necessary for integrated grassland and forest management in the face of climate variability and change. In this study, we sought to establish a relationship between remote sensing-derived vegetation indices (VIs) and dendrochronological (raw and standardized tree ring width) measurements to assess the performance of encroaching woody J. virginiana and P. ponderosa located within the Nebraska National Forest in the sandhills. …

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

USDA Forest Service / UNL Faculty Publications

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …

Validity And Reliability Of Drought Reporters In Estimating Soil Water Content And Drought Impacts In Central Europe, Lenka Bartošová, Milan Fischer, Jan Balek, Monika Bláhová, Lucie Kudláčková, Filip Chuchma, Petr Hlavinka, Martin Možný, Pavel Zahradníček, Nicole Wall, Michael Hayes, Christopher Hain, Martha Anderson, Wolfgang Wagner, Zdeněk Žalud, Miroslav Trnka

School of Natural Resources: Faculty Publications

Increasing drought is considered one of the major threats associated with climate change in central Europe. To provide an objective, quantitative tool that represents current drought conditions, the Czech Drought Monitor System (CzechDM) was established in 2012. Like other drought monitoring systems worldwide, the CzechDM uses several approaches to provide drought data. However, the CzechDM is unique internationally due to its utilization of a network of voluntary reporters (farmers) who complete a weekly online questionnaire to provide information about soil water content and the impacts of drought on crop yield. In this study, the results from the questionnaires from individual …

Planning Strategies And Barriers To Achieving Local Drought Preparedness, T. Haigh, E. Wickham, S. Hamlin, C. Knutson

School of Natural Resources: Faculty Publications

No abstract provided.

A Statistical Evaluation Of Earth-Observation-Based Composite Drought Indices For A Localized Assessment Of Agricultural Drought In Pakistan, C. Schwartz, W. Lee Ellenburg, V. Mishra, T. Mayer, R. Griffin, F. Qamer, M. Matin, Tsegaye Tadesse

School of Natural Resources: Faculty Publications

No abstract provided.

When To Prepare: "Water" You Thinking About Drought?, O. G. Campbell, C. Schwartz, Deborah J. Bathke

School of Natural Resources: Faculty Publications

No abstract provided.

Polycentric Governance In Nebraska, U.S., For Ground And Surface Water, Theresa Jedd, Anthony B. Schutz, Mark Burbach

School of Natural Resources: Faculty Publications

This chapter describes the locally driven, but centrally coordinated, water governance model in Nebraska, U.S. It offers a snapshot of water resources and the importance of agriculture, then moves to the relevant political institutions in the state, and federal controls related to water quantity. The focus of the chapter is on the Nebraska Department of Natural Resources’ (NeDNR) and Natural Resources Districts’ (NRDs) management of surface and groundwater, which has some distinct and some overlapping authority. The main area of overlap is in addressing the connection between ground and surface water, particularly in situations when either or both are over …

Evidence For Irruptive Fluctuation In Axis Deer Of Hawai‘I, Steven C. Hess, Jonathan Sprague, Jacob Muise

USDA Wildlife Services: Staff Publications

Axis deer on the Hawaiian Islands of Maui, Lāna‘i, and Moloka‘i simultaneously experienced one of the most dramatic population crashes on record in 2020-2021, which coincided with extended drought conditions and prompted an emergency declaration for these islands. This phenomenon has been anecdotally documented during previous drought events in 2011-2012, but never formally studied. Newspaper articles document abundant deer becoming a nuisance to agriculture and natural resources, and then experiencing high mortality during droughts. This phenomenon fits Caughley’s (1970) operational definition of eruptive (sic) fluctuation “…as an increase in numbers over at least two generations, followed by a marked decline.” …

An Integrated Food, Energy, And Water Nexus, Human Well-Being, And Resilience (Few-Wise) Framework: New Mexico, Kamini Yadav, Hatim M. Geli, Andres F. Cibils, Michael Hayes, Alexander Fernald, James Peach, Mohammed N. Sawalhah, Vincent C. Tidwell, Lindsay E. Johnson, Ashraf J. Zaied, Melakeneh G. Gedefaw

School of Natural Resources: Faculty Publications

Interconnected food, energy, and water (FEW) nexus systems face many challenges to support human well-being (HWB) and maintain resilience, especially in arid and semiarid regions like New Mexico (NM), United States (US). Insufficient FEW resources, unstable economic growth due to fluctuations in prices of crude oil and natural gas, inequitable education and employment, and climate change are some of these challenges. Enhancing the resilience of such coupled socio-environmental systems depends on the efficient use of resources, improved understanding of the interlinkages across FEW system components, and adopting adaptable alternative management strategies. The goal of this study was to develop a …

Informing Drought Mitigation Policy By Estimating The Value Of Water For Crop Production, Renata Rimsaite, Justin Gibson, Nicholas Brozovic

School of Natural Resources: Faculty Publications

Farmers use irrigation to mitigate drought risk and reduce yield uncertainty. A clear understanding of the monetary value of irrigation water and how it varies across time and space can help to inform farmers and policymakers about the potential impacts of water shortages and reduce uncertainty in decision making. Here, we introduce a framework for understanding the economic value of water used to produce corn in the central High Plains region during the period 2010–2017. Our analysis uses publicly available data for corn price and for irrigated and non-irrigated yields and incorporates irrigation requirement adjustments to account for the hydrologic …

Effects Of Drought On Groundwater-Fed Lake Areas In The Nebraska Sand Hills, N. Shrestha, A. R. Mittelstet, T. E. Gilmore, V. Zlotnik, C. Neale

School of Natural Resources: Faculty Publications

No abstract provided.

Ranchers’ Use Of Drought Contingency Plans In Protective Action Decision Making, Tonya Haigh, Michael Hayes, Jolene Smyth, Linda Stalker Prokopy, Charles A. Francis, Mark Burbach

Drought Mitigation Center: Faculty Publications

Drought contingency planning is an increasingly common tool in the ranchers’ climate adaptation toolboxes, but its effect on drought response has not yet been evaluated. We use cognitive models of protective action decision making and planning to explore the effects of having a drought plan on the use of drought early warning information and drought response (and timing). Results of a cross-sectional, probability-based survey of livestock producers affected by a 2016 flash-drought are used to describe the characteristics of operations with drought plans and provide evidence of whether having a plan predicts drought information use and response. While larger operations …

Building An Improved Drought Climatology Using Updated Drought Tools: A New Mexico Food-Energy-Water (Few) Systems Focus, Lindsay E. Johnson, Hatim M.E. Geli, Michael J. Hayes, Kelly Helm Smith

Drought Mitigation Center: Faculty Publications

Drought is a familiar climatic phenomenon in the United States Southwest, with complex human-environment interactions that extend beyond just the physical drought events. Due to continued climate variability and change, droughts are expected to become more frequent and/or severe in the future. Decision-makers are charged with mitigating and adapting to these more extreme conditions and to do that they need to understand the specific impacts drought has on regional and local scales, and how these impacts compare to historical conditions. Tremendous progress in drought monitoring strategies has occurred over the past several decades, with more tools providing greater spatial and …

Connections Between The Hydrological Cycle And Crop Yield In The Rainfed U.S. Corn Belt, Wang Zhou, Kaiyu Guan, Bin Peng, Jiancheng Shi, Chongya Jiang, Brian Wardlow, Ming Pan, John S. Kimball, Trenton Franz, Pierre Gentine, Mingzhu He, Jingwen Zhang

School of Natural Resources: Faculty Publications

No abstract provided.

Habitat Patchiness, Ecological Connectivity And The Uneven Recovery Of Boreal Stream Ecosystems From An Experimental Drought, Amelie Truchy, Romain Sarremejane, Timo Muotka, Heikki Mykra, David G. Angeler, Kaisa Lehosmaa, Ari Huusko, Richard K. Johnson, Ryan A. Sponseller, Brendan G. Mckie

School of Natural Resources: Faculty Publications

Ongoing climate change is increasing the occurrence and intensity of drought episodes worldwide, including in boreal regions not previously regarded as drought prone, and where the impacts of drought remain poorly understood. Ecological connectivity is one factor that might influence community structure and ecosystem functioning post-drought, by facilitating the recovery of sensitive species via dispersal at both local (e.g. a nearby habitat patch) and regional (from other systems within the same region) scales. In an outdoor mesocosm experiment, we investigated how impacts of drought on boreal stream ecosystems are altered by the spatial arrangement of local habitat patches within stream …

Whose Ground Truth Is It? Harvesting Lessons From Missouri’S 2018 Bumper Crop Of Drought Observations, Kelly Helm Smith, Mark E. Burbach, Michael J. Hayes, A. Tyre, Patrick E. Guinan, Brian Fuchs, Tonya Haigh, Mark D. Svoboda

School of Natural Resources: Faculty Publications

No abstract provided.

Czech Drought Monitor System For Monitoring And Forecasting Of Agricultural Drought And Drought Impacts, Miroslav Trnka, Petr Hlavinka, Martin Možný, Daniela Semerádová, Petr Štěpánek, Jan Balek, Lenka Bartošová, Pavel Zahradníček, Monika Bláhová, Petr Skalák, Aleš Farda, Michael Hayes, Mark D. Svoboda, Wolfgang Wagner, Josef Eitzinger, Milan Fischer, Zdeněk Zalud

School of Natural Resources: Faculty Publications

The awareness of drought and its impacts on Central Europe increased after the significant drought episodes in 2000, 2003, 2012 and 2015, which were all estimated to have caused over 500 million Euro in damage in the Czech Republic alone. These events indicated the need for timely and highresolution monitoring tools that would enable analysing, monitoring and forecasting of drought events. Monitoring soil water availability in near real time and at high-resolution (up to 0.5 × 0.5 km for some products) helps farmers and water managers to mitigate impacts of these extreme events. The Czech Drought Monitor was developed between …

Multi-Dimensional Nature Of Drought In Abbay/Upper Blue Nile Basin And The Importance Of Regional Coordination Efforts For Mitigation, Y.A. Bayissa, S. Moges, A.M. Malesse, T. Tadesse, A.Z. Abiy

School of Natural Resources: Faculty Publications

No abstract provided.